French author whose early works exemplify the naturalist (naturalism) and Symbolist (Symbolist movement) schools and who later won a considerable reputation for his historical and sociological novels.

Publication of his first naturalist novel, Chair molle (1885), led to his being prosecuted; his second, Le Thé chez Miranda (1886), written with Jean Moréas (Moréas, Jean), is an early example of Symbolism. Adam also founded two literary reviews in 1886: Led Carcan, with Jean Ajalbert, and the short-lived Le Symboliste, with Moréas and Gustave Kahn (Kahn, Gustave). In 1899, with La Force, Adam began a series of novels depicting French life during the period 1800–30; the last, Au soleil de Juillet, appeared in 1903. He travelled widely and wrote two books on his American journeys, Vues d'Amérique (1906) and Le Trust (1910). His autobiography, in the form of a novel, Jeunesse et amours de Manuel Héricourt, appeared in 1913.